Here's a bit of an odd thought for the day: It first happened with Bluetooth not so long ago: With its data rate limited to 2-3 MBit/s, Bluetooth is no longer capable of forwarding data between let's say a PC and a phone at full HSDPA speeds offered today in networks. As reported here, I get more than 5 MBit/s with a HSDPA category 8 device in a live network.
With the most popular Wi-Fi variant currently used, i.e. 802.11g with a raw data rate of 54 MBit/s and a practical maximum throughput of around 20 MBit/s, similar things will happen once we go to HSPA+ with data rates of 21 and 28 MBit/s and beyond.
Sure there's 802.11n that is capable of much more but it requires several antennas and its unlikely that we'll see it in mobile devices with several antennas anytime soon. But then, the thought is mainly academical anyway these days. While I used to tether my PC and mobile phone quite a lot in the past I only resort to it seldomly these days. In most countries, an extra (prepaid) SIM card for the PC for wireless broadband has become so affordable that I'd rather spend a bit more money than to go through the hassle of tethering.
But still, the thought shows nicely how technology has progressed over the past few years, with a wide area network technology now at the brink of surpassing the speed of a short range wireless technology that was only a couple of years ago thought of as being super fast.